Methods are known for fixing an elastic element or member, such as an elastomeric band or ribbon, to a flexible, substantially inelastic web of material defining clothing or compounds thereof, including briefs, panty briefs, disposable diapers, and the like.
Methods are known for applying an elastic element to a continuously moving web. The U.S. Pat. No. 3,828,367 to Bourgeois discloses a method for securing a stretched elastic element to a non-elastic fabric web and maintaining the assembled element on the web in a stretched condition until cut transversely of the direction of travel to produce separated panels. The apparatus is disclosed as including a rotating cylinder with a curved guide for imparting a non-linear configuration to the elastic element so that the ribbon follows a predetermined contour on the non-elastic fabric.
With the method disclosed in the above-discussed Bourgeois patent, the elastic thread to be laid in a non-linear configuration contains adhesive on its surface and must be of a sufficient thickness to allow the elastic thread to be compressed during application to facilitate adhesion. This thick elastic produces a thickened elastic portion in the final product. Also in the apparatus disclosed, the use of the more common liquid adhesives is not indicated as they would tend to deposit and "gum up" the guiding grooves as well as the roll surfaces.
The U.S. Pat. No. 4,081,301 to Buell cites other prior art patents showing ways in which an elastic ribbon is joined to a moving web of material. The Buell patent itself discloses a method and apparatus for continuously attaching discrete lengths of elastic ribbon to a moving web in which the elastic ribbon is fed in a stretched condition to the web and in which the elastic ribbon is intermittently secured to predetermined regions of the web while so stretched. Subsequently, the web and elastic ribbon are transversely cut in an area where the elastic ribbon is not secured to the web, thereby forming severed, unadhered portions of elastic at both ends of each discrete length of stretched elastic ribbon adhered to the web and allowing the severed, unadhered ends of the elastic ribbon to relax and contract to their unstretched state. The method disclosed in the above-discussed Buell patent provides for the elastic to be laid in a linear configuration and no technique for providing for a non-linear configuration of the elastic thread is disclosed.
In order to avoid the undesirable thickening of the area where an elastic member is inserted and to allow the use of elastic members of various configurations such as, film, ribbon, filaments, and the like, it would be desirable to provide a method and apparatus in which any type of elastic member could be laid in a non-linear configuration and secured to the moving web in that configuration.